Vat dyestuffs of the anthraquinone series



Patented Sept. 26, 1933 I U NITED, STATES A ENT; VAT- DYESTUFFS OF THE ANTHRAQUINONE a SERIES 05kt UngergLudwigshafen on the lthine, "and j Georg Boehner, Edingen-on-the -Neckar," Gerl many, assignors to General Aniline Works 1110., I liew york, N. 1L, a corporation of Delaware 1 Drawing Application May 3, 1929, Serial No r 360,322, and in Germany May 10, 1928 4 Claims; j (01. 260-60) Theflpresent invention relates to the production of vat dyestufislot the anthraquinone series containing sulphur.

We have found that valuable vat dyestuffs of the anthraquinone series, namely the technically im p o r t a n t C-diaryl-2.1(S) -6.5(S) -anthraquinonedithiazoles, can be advantageously prepared by treating with sulphur, or agents furnishing the same, the imidechlorides of 2.6-diaroyl-diaminoanthraquinone or substitution products thereof corresponding to the general formula V in which R and R stand for aryl radicles. The said imidechlorides can-be obtained, for example, by the action of phosphorus pentachloride on 2.6-diaroyl-diaminoanthraquinones,' the latter being obtainable according to Bulletin de la Socit, Chimique de France .(4) Vol. 29, 1921,

pages 1027 7001036. If the sulphurizing of the imidechlorides be performed under mild conditions, for example at low temperature, intermediate products can be obtained which, from their analytical data and reactions are probably 2 .6- bisarylmercaptomethylimino anthraquinones of the general formula:

' are for example sulphuric acid, chlorosulfonic acid and the like, to which an oxidizing agent, for instance manganese dioxide, may be added. Al kaline oxidizing agents, for example caustic alkali solution containing potassium ferricyanide, may also be used.

The following examples will'further illustrate the nature of the invention which however is r 20 parts of potassium hydroxide are dissolved The reaction product is soluble in trichloroben notrestricted to these examples. Theparts are by weight.

' Example! anthraquinone, obtainable in the form of yel- 20 parts of 2.6-bis-pheny1chlormethylimino low needles melting at about 256 centigrade by t r e a t in g 2.65dibenzoyldiaminoanthraquinone with phosphorus penta-chloride, are heated with 80 parts of naphthaleneand 40 parts of sulphur, under a reflux condenser, until no imidechloride remains.

The cooled melt is freed from naphthalene by extraction with an organic solvent; The C-diphenyl- 2.1 -'(S) -6.5 (S) '-anthraquinonedithiazole thus obtained remains behind in the form of a yellow green powder. 1

' Examplez f in 200 parts of alcohol and the solution is saturated with sulphuretted hydrogen. 20 parts of 2.6 -'bis phenylchlormethyliminoanthraquinone are then added, and the mixture is boiled under a're'flux condenser until all the 2.6-bis-phenylchlormethyliminoanthraquinone has disappeared. The mixture is then diluted with hot water until solution is effected, being then filtered, and the yellow brown filtrate is treated with hydrochloric acid and worked up in the usual manner. reaction product is a yellow amorphous substance, which dissolves to a yellow solutionin dilute caustic alkalis, and may be regarded as 2.6 -bisphenylmercaptomethyliminoant h r a on in on e.

zene, from which it crystallizes out, on cooling in The the form of brown-yellow acicular tufts, and

melts at above 360 centigrade.

Example 3 20 parts of the reaction product describedin Example 2 are dissolved in 400 parts of a 96 per cent sulphuric acid solution, the solution. being then warmed to, about centigrade until the formation of the dyestuff is completed. After cooling, the reaction mass is diluted with water,

and the precipitated C-dipheriyl-Zl-(S) 6.5-.(S)

anthraquinonedithiazole is further treated in the usual manner. I

placed by chlorosulphonic acid or sulphuric monohydrate, or a mixture of these acids, the formae tion of the dyestufi occurs at lower temperatures.

In the above described preparation'of the dithiazole from 2.6-bis-phenylmercaptomethylimino- If the 96 per cent sulphuric acid solution be reanthraquinone, oxidizing agents, such as man-- The conversion of the intermediate product, de-' scribed in Example 2, into C-diphenyl-2.1- ('S) 6.5-(S) anthraquinonedithiazole can also be effected in an alkaline medium, for example by boiling with asolution of potassium ferricyanide e thraquinone with a sulphurizing agent.

' 3-. Intheproductioh of intermediate products and vat dyestuffs of the, anthraquinone series con taining sulphur the step, which comprises heating an I imidechloride 'of a 2.6-dibenzoyldiaminoancontaining caustic alkali. j

What we claim is: 1. As, a new article of e phenylmercaptomethyliminoan th -1' a q ui' n o n e probably corresponding to the formula:

manufacture crystallizing inthe form of brown yellow acicular tufts from trichlorbenzene, melting above 36 0 centigrade and dissolving in dilute caustic alkali.

solution, giving a yellow solution. 7 4

and vat'dyestuifs of the anthraquinone series containing sulphur the step, which comprises heating an imidechlor-ide of a 2.6-dibenzoyldiaminoanthraquinone with sulphur in naphthalene; v

4. In the production of intermediate products and vat dyestuffs of fthe .anthraquinone series containing sulphur the step, which comprises heating the 'imidechloride of 2.6-dibenzoyldiaminoanthraquinone with sulphur-in naphtha- A J lene. 

